A/T - No Reverse, New Rear Band 4L80E
Number: 92-229-7ASection: 7A
Date: JUNE 1992
Corporate Bulletin No.: 277125R
ASE No.: A2
Subject:
NO REVERSE
Model and Year:
1991-92 C/K, R/V, G, P TRUCKS WITH 4L80E/4L80EHD AUTOMATIC TRANSMISSION
TRANSMISSION APPLICATIONS:
1991-92 HYDRA-MATIC 4L80-E/4L80-EHD (MT1)
TRANSMISSION MODELS:
All Models
SUBJECT:
Anchor Lug Fatigue (New Rear Band Assembly)
VEHICLE APPLICATIONS:
C, K, R, V and P Trucks G-Van
CONDITION:
Some HYDRA-MATIC 4L80-E/4L80-EHD Transmissions may experience a no reverse condition.
CAUSE:
This is caused by the lugs on the rear band assembly not holding to the case pins, causing the reaction drum not to hold.
CORRECTION:
A new Rear Band Assembly was released to eliminate anchor lug fatigue.
DATE OF PRODUCTION:
(Figures 1 & 2) Starting April 11, 1992 (Julian Date 101) all 4L80-E/4L80-EHD were built with this new Rear Band Assembly.
SERVICE PART INFORMATION:
8681620 Band Assembly, Rear Brake
Parts are currently available at GMSPO.
SERVICE PROCEDURE:
(Figure 3) On all 1991 vehicles, the Band Assembly and Case Assembly with added ribs to strengthen the anchor pin area must be serviced together. All 1992 vehicles have the new case assembly, only the Band Assembly is serviced. Refer to your appropriate catalog for correct case assembly numbers.
The previous Band Assembly (8677313) can be used, until new bands are available, if the band has a blue ink stamp 295 or has an identification date stamp.